Various technologies have been proposed as a vehicle occupant protection device for protecting an occupant of a vehicle from a collision.
For example, in the technology disclosed in Japanese National Phase Publication No. 2007-500650, it is proposed to predict an accident, in which there is a possibility that a vehicle will become involved, by a sensor such as a radar sensor, a video sensor, a laser scanner-based sensor or the like, and in a case where an accident has been predicted, adjust a seat back at a speed that is faster than an adjustment speed at a time of adjusting an angle of the seat back.
Further, in the technology disclosed in Japanese Patent No. 2946995, it is proposed to predict a collision of a vehicle and operate a first pretensioner mechanism, and to judge the collision and operate a second pretensioner mechanism.
As discussed above, various technologies have been proposed for a vehicle occupant protection device, and protecting a vehicle occupant with even greater certainty by combining these technologies can also be considered. For example, in a case where a collision has been predicted, adjusting an angle of a seat back together with operating a pretensioner mechanism to apply tension to a seatbelt can be considered.
However, although the seat back can be moved to an appropriate state before the collision by predicting the collision and adjusting the seat back, if, at the time of this operation, tension is applied to the seatbelt by the pretensioner mechanism being operated, and the movement of the seat back and the application of tension to the seatbelt continue to be carried out simultaneously, the load of a motor that drives the seat back or the like may increase to cause the motor to break down, or excessive load may be applied to the vehicle occupant, and thus, there is room for improvement.